<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>九宫格</title>
    <style>
        .square {
            width: 32%;
            height: 32vw;
            margin-left: 1vw;
            margin-top: 1vw;
            background: orange;
            border-radius: 5%;
            float:left
        }
    </style>
</head>
<body style="margin: 0">
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>
    <div class="square"></div>  
</body>
</html>